Researchers found high-fat foods damage the circuit responsible for losing weight.
The University of Aberdeen study suggests that calorie-control diets are ineffective in keeping weight off, while the key to staying slim is to significantly reduce fat intake.
It found that the brain’s energy balance circuit, which plays a key role in the body’s natural weight control, acts as a “thermostat” in weight gain.
Experts believe that simply eating less but still eating unhealthily does not work because high-fat foods inhibit the circuit’s ability to regenerate itself, leading to weight gain.
It highlights the importance of preventing the weight gain in childhood
They found that the circuit, just above the brain stem, is able to regenerate faster and speed up a person’s metabolism on a low-fat diet. The research shed light on how dieters will be able to lose weight without yo-yo dieting and help tackle Scotland’s burgeoning childhood obesity crisis.
Figures released by the Scottish Government in June revealed that almost one in five young children are now dangerously overweight.
Aberdeen University researcher David McNay said: “We have known for some time that over-eating an unhealthy diet causes obesity, but we have not been sure if it was the overeating or the unhealthy diet that is the problem.
“This research shows that every calorie is not equal and that successful treatment of obesity requires both eating less and eating healthier.”
Dieticians say the research highlights the pitfalls in crash diets that result in rapid weight loss but use high-fat foods like meat and cheese.
Kristian Bravin, of the British Dietetic Association, said: “This study supports the role of a balanced diet from an early age.
“We know that high-calorie and fat diets, along with limited physical activity, contribute to obesity and that many people put on more weight having followed a ‘successful’ restrictive diet.
“This study suggests a possible mechanism why this should happen. It highlights the importance of preventing the weight gain in childhood by encouraging a diet high in fruit, vegetables, wholegrain cereals and a low to moderate fat intake.
“It also highlights a possible reason why diets that promote rapid weight loss and diets that are high in fat but low calories do not lead to long-term weight loss.”
The research was funded by Action Medical Research and was published in Molecular Metabolism.